demo1.m

gmm gmr gmm gmr

function demo1
%
% Demo of the generalization process using Gaussian Mixture Regression
% (GMR). This software loads a 3D dataset, trains a Gaussian Mixture Model 
% (GMM), and retrieves a generalized version of the dataset with associated 
% constraints through Gaussian Mixture Regression (GMR). Each datapoint 
% has 3 dimensions, consisting of 1 temporal value and 2 spatial values 
% (e.g. drawing on a 2D Cartesian plane). A sequence of temporal values is 
% used as query points to retrieve a sequence of expected spatial 
% distributiuon through Gaussian Mixture Regression (GMR).
%
% Copyright (c) 2006 Sylvain Calinon, LASA Lab, EPFL, CH-1015 Lausanne,
%               Switzerland, http://lasa.epfl.ch
%
% The program is free for non-commercial academic use. 
% Please contact the authors if you are interested in using the 
% software for commercial purposes. The software must not be modified or 
% distributed without prior permission of the authors.
% Please acknowledge the authors in any academic publications that have 
% made use of this code or part of it. Please use this BibTex reference: 
% 
% @article{Calinon06SMC,
%   title="On Learning, Representing and Generalizing a Task in a Humanoid 
%     Robot",
%   author="S. Calinon and F. Guenter and A. Billard",
%   journal="IEEE Transactions on Systems, Man and Cybernetics, Part B. 
%     Special issue on robot learning by observation, demonstration and 
%     imitation",
%   year="2006",
%   volume="36",
%   number="5"
% }

%% Definition of the number of components used in GMM.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
nbStates = 4;

%% Load a dataset consisting of 3 demonstrations of a 2D signal.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
load('data/data1.mat'); %load 'Data'
nbVar = size(Data,1);

%% Training of GMM by EM algorithm, initialized by k-means clustering.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
[Priors, Mu, Sigma] = EM_init_kmeans(Data, nbStates);
[Priors, Mu, Sigma] = EM(Data, Priors, Mu, Sigma);

%% Use of GMR to retrieve a generalized version of the data and associated
%% constraints. A sequence of temporal values is used as input, and the 
%% expected distribution is retrieved. 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
expData(1,:) = linspace(min(Data(1,:)), max(Data(1,:)), 100);
[expData(2:nbVar,:), expSigma] = GMR(Priors, Mu, Sigma,  expData(1,:), [1], [2:nbVar]);

%% Plot of the data
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure('position',[10,10,1000,800],'name','GMM-GMR-demo1');
%plot 1D
for n=1:nbVar-1
  subplot(3*(nbVar-1),2,(n-1)*2+1); hold on;
  plot(Data(1,:), Data(n+1,:), 'x', 'markerSize', 4, 'color', [.3 .3 .3]);
  axis([min(Data(1,:)) max(Data(1,:)) min(Data(n+1,:))-0.01 max(Data(n+1,:))+0.01]);
  xlabel('t','fontsize',16); ylabel(['x_' num2str(n)],'fontsize',16);
end
%plot 2D
subplot(3*(nbVar-1),2,[2:2:2*(nbVar-1)]); hold on;
plot(Data(2,:), Data(3,:), 'x', 'markerSize', 4, 'color', [.3 .3 .3]);
axis([min(Data(2,:))-0.01 max(Data(2,:))+0.01 min(Data(3,:))-0.01 max(Data(3,:))+0.01]);
xlabel('x_1','fontsize',16); ylabel('x_2','fontsize',16);

%% Plot of the GMM encoding results
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%plot 1D
for n=1:nbVar-1
  subplot(3*(nbVar-1),2,4+(n-1)*2+1); hold on;
  plotGMM(Mu([1,n+1],:), Sigma([1,n+1],[1,n+1],:), [0 .8 0], 1);
  axis([min(Data(1,:)) max(Data(1,:)) min(Data(n+1,:))-0.01 max(Data(n+1,:))+0.01]);
  xlabel('t','fontsize',16); ylabel(['x_' num2str(n)],'fontsize',16);
end
%plot 2D
subplot(3*(nbVar-1),2,4+[2:2:2*(nbVar-1)]); hold on;
plotGMM(Mu([2,3],:), Sigma([2,3],[2,3],:), [0 .8 0], 1);
axis([min(Data(2,:))-0.01 max(Data(2,:))+0.01 min(Data(3,:))-0.01 max(Data(3,:))+0.01]);
xlabel('x_1','fontsize',16); ylabel('x_2','fontsize',16);

%% Plot of the GMR regression results
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%plot 1D
for n=1:nbVar-1
  subplot(3*(nbVar-1),2,8+(n-1)*2+1); hold on;
  plotGMM(expData([1,n+1],:), expSigma(n,n,:), [0 0 .8], 3);
  axis([min(Data(1,:)) max(Data(1,:)) min(Data(n+1,:))-0.01 max(Data(n+1,:))+0.01]);
  xlabel('t','fontsize',16); ylabel(['x_' num2str(n)],'fontsize',16);
end
%plot 2D
subplot(3*(nbVar-1),2,8+[2:2:2*(nbVar-1)]); hold on;
plotGMM(expData([2,3],:), expSigma([1,2],[1,2],:), [0 0 .8], 2);
axis([min(Data(2,:))-0.01 max(Data(2,:))+0.01 min(Data(3,:))-0.01 max(Data(3,:))+0.01]);
xlabel('x_1','fontsize',16); ylabel('x_2','fontsize',16);

pause;
close all;